Printhead calibration and printing
US9427963B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 2013 |
| Grant date | Aug 30, 2016 |
| Priority date | — |
| Expiry date | Sep 17, 2033 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2002/022
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method of calibrating a printhead, for printing two-dimensional bit-mapped images having a number of pixels per row, is disclosed for printheads (1) having a row of printing channels (5). During printing, in order to cause volumes of charged particulate concentrations of one of a number of predetermined volume sizes to be ejected from selected ejection channels of the printhead to form printed pixels, control pulse values of respective predetermined amplitude and duration, as determined by respective image pixel bit values, are applied to the selected printing channels. The calibration method comprises providing an image (50) that causes each channel of the printhead to be driven with the same pulse value, and printing one or more test prints of the image. The pulse value for all channels is then varied (101) in a set of defined steps within the test print or between the test prints and the optical density of the test print or test prints measured (102) at positions arranged on a grid (51) to obtain data of print density and pulse value at positions across the printhead. A desired tone reproduction curve (52) is pre-selected for the print process represented by optical density ve…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.